Liquid piston air compressor



Aug. 14, 1951 E. SJBERG LIQUID PISTON AIR COMPRESSOR 2 Sheets-Sheet 1 Filed Dec. 3, 1947 Aug. 14, 1951 E. SJBERG LIQUID PISTON AIR COMPRESSOR 2 Sheets-Sheet 2 Filed Dec. 3, 1947 jatented ug. 14, i951 LIQUID PISTON AIR vCOIHPRESSOR Edvin Sjberg, Mariehall, near Stockholm, Sweden Application December 3, 1947, Serial No. 789,492 In Sweden November 13, 1944 Section 1, Public Law 690, August 8, 1946 Patent expires November 13, 1964 14 Claims.

The present invention relates to water receptacles or water tanks having means supplying water into the receptacle or tank and a discharge valve provided in the bottom of the receptacle or tank.

A broad object of the invention is to provide a device effective for opening a discharge value automatically when the receptacle is substantially lled with water, and a special object is to effect this by means of mechanisms which are of simple design and are reliable in operation.

According to a generic feature of the invention the water discharge valve is operated from a float by means of an actuator mechanism comprising a vertical rod and two different spring connections, of which, one is arranged between said discharge Valve and the lower end of said rod and the other is arranged between said float and the upper end of said rod, this last-mentioned spring connection being more elastic or weaker than is the resilient connection of the discharge valve, to allow this valve to open with a delay in relation to the lifting movement of the float.

According to another feature of the invention a chamber housing said float is provided with discharge means adapted to discharge the float chamber only when the water receptacle is substantially discharged, so as to cause the float to close the discharge valve of the water receptacle after the water receptacle has been substantially discharged.

In this broad aspect of the invention the discharge device may be used for discharging water receptacles of any kind, for instance flushing cisterns for urinals.

According to a more specific feature of the invention the Water receptacle is hermetically closed or sealed and has an air inlet opening provided in the upper portion of the water receptacle, as well as a valve controlling this air inlet, and a conduit connected to said upper portion of the receptacle, to constitute a consumption conduit for air under pressure compressed by the rising Water column Within the receptacle.

In this more restricted form the receptacle provided with the devices according to the invention, constitutes a hydraulic air compressor delivering a clean and odorless air under such pressure, that this air may be used for retailing drinks, for instance milk, furthermore in dentists equipments, divers equipments and the like, where a clean and non-smelling pressure air is important.

The features of the invention and further objects of the same will be more clearly understood by the following detailed description of embodiments illustrated diagrammatically in the accompanying drawings, in which:

, Fig. l is a sectional elevation of an embodiment of a hydraulic air compressor according to the invention;

Fig. 2 is a similar elevation of a modified embodiment of an air compressor according to the invention, wherein substantially only the modied details are shown;

Fig. 3 is a sectional elevation of an embodiment of a flushing cistern for urinals, according to the invention.

In the drawings corresponding details of the discharge device are indicated by similar reference numerals throughout the several embodiments.

In Fig. l, the hydraulic air compressor comprises a receptacle |00 having a bottom |0| and an airtight closure or cover |03. Said receptacle is preferably made as a' cylinder. In connection with this cylinder there is arranged an air reservoir |02 which could be made as a part of said cylinder, for instance by a partition in the upper portion of said cylinder, but which in this embodiment is shown as an annular chamber surrounding said cylinder. Said airtight receptacle |00 serves as a water container in which a rising column of Vwater supplied at the bottom |0 compresses the air admitted into the upper portion of the cylinder |00, the air reservoir |02 being supplied with the air so compressed.

The Water receptacle |00 is provided with a float chamber |04 which is arranged within the cylinder, near the upper end of the same, and is secured to the cylindrical wall by suitable fastening means, for instance intermediate bodies |05 attached to the cylindrical wall and to the float chamber by welding or the like. Said float chamber is open at the upper end surface of the same. Thus, the float chamber is filled only in the way that the rising water of the cylinder ultimately flows over the rim of the float chamber, and this rim lies at a level comparatively high in the cylinder |00. Through said iioat chamber a vertical tube |06 extends which is sealed to the bottom of said chamber and in which a rod |01 is slidable with some clearance. The float |08 is guided upon said tube |06 by means of a tube |09 which projects from the upper face of the float and is provided with two slots I i0 which are in diametrically opposed positions and which terminate a short distance below the upper end of the tube |0l9. By means of the slotted tube |09 the float |08 is suspended on a cross pin secured in a radial aperture made through the rod |01.

A helical spring |I2 is arranged between said pin II I and the upper face of the float |08. The lower end of the rod |01 is by means of a second helical spring I |3 connected with a valve I |4 controlling a discharge opening from the water container, this valve being normally closed. This discharge opening may be the central opening of a sleeve |I5 which is securely mounted in the container bottom |I. The valve II4 may be a ball composed of an elastic material, secured on a guiding stem II6. This valve stem has on its upper end an extension made as a sleeve I'I1 constituting a housing for the spring II3. It is toV be noted that the spring ||2 is lighter or weaker than is the spring I3. From the discharge sleeve the water flows into an outlet chamber ||9 in which the lower end of the sleeve I I5 is secured by means of a positioning ring |20 having openings through which the interior of this chamber communicates with the ambient air. From the discharge chamber I |9 an outlet or discharge pipe I2| extends. A discharge opening |23 is provided also in the bottom of the oat chamber. This discharge opening is controlled by a valve |24 supported by a lever |25. This lever is operated by a float |26 secured to one end of this lever. The other end of said leverl is journalled on a horizontal axis |21 supported in a bracket |26 on the float chamber, means being provided to allow only a limited movement of the lever |25 downwards, for instance stop surfaces on the lever and in the bracket, respectively.

Water under pressure is supplied to the water container |60 through a conduit |30, which may contain a shut-ofi valve` (not shown) over a regulator valve I3 I, a second conduit |32, and a water inlet |33 provided in the container bottom. The regulator valve I3I is automatically operated in dependence on the air pressure in the air reservoir |02 and thus in dependence on the air pressure in the upper portion of the water container |604. In the embodiment shown the regulator valve |3I is normally held in open position by a spring |35, against the action of said air pressure. For instance, the spring |35 is disposed between a foot plate on the valve stem |36 and screw means |31 serving to adjust the tension of the spring, and said foot plate rests against a piston or other movable wall portion of an air pressure chamber |39, such as an elastic vdiaphragm |38 constituting one wall of said chamber |39. The interior of this pressure chamber is connected yto the air reservoir |02 through an air conduit |40, an air tapping or discharging means |4| being provided within said reservoir in `connection with said conduit. Thus, the arrangement is such, that a certain pressure of the `air above atmospheric, enclosed within the upper portion of the water container and within the air reservoir, will cause closing of the regulator valve I3 Y The water inlet opening |33 arranged in the bottom of the water container |00, is controlled by a valve |45 operating in dependence on the water level Within the water container in a manner so as to avoid overlling of the water container. For this purpose the water inlet valve |45 may be operated from a lspecial float arranged within the upper portion of the water container and connected with said valve by means of a lever mechanism, but it will also be possible to operate said valve from the main float |08, for instance in the lfollowing way. The water inlet valve |45 is supported by one en d of a lever |46 journalled in a bracket |41. The other end of said lever has an extension consisting of Aa rod |48 which exshaped like a plate.

tends through a radial aperture made in the stem I I6 oi the discharge valve I I4, or is coupled with this stem in any other Way. The arrangement is such that the water inlet |33 is open when the valve I4 is in the closed position, and vice versa. Thus, the water inlet valve ,I 45 is loperated `automatically by the water discharge valve |I4 and thereby in dependence of the water level within the water container.

Into the upper portion of the water container |00 fresh air is supplied through an air filtering apparatus (not shown), through an air inlet |50 which extends through a body I5| securely mounted within the container |00 and being Y This body I5I carries a bracket |52 in which a valve element |53 is journalled on a horizontal axis |54. Said valve element is provided with two valves |55 and |51. One of these two valves, in this instance, the lower valve |56, cooperates with the opening of the air inlet |50. The other, thus .the upper valve |51, cooperates with an air outflow opening |58 communicating with a channel (not shown) made in said body |5| and being connected witha 'conduit |59 extending into the air reservoir |92. The air inlet valve |56 isoperated in dependence on the water level in the. float chamber |764 in such manner, that said valve |56 is normally closed but is brought to open position when Vthe water container and the oat chamber |04 are substantially filled; at the same time the air outflow valve |51 is either in open position or in closedV position.

This may be effected by means of a lever mechanism connecting said valve element |53 directly with the oat rod |01, but according to the embodiment shown in Fig. l the following arrangement is used. The Vvalve element |53 carries an extension rod |66 which supports a float |6| and which cooperates with the upper end of the vertical rod |01, this upper end being provided with a fork-shaped member |62, adapted to lift the valve lever |60 and thus t0 open the air inlet |56, at the same time as the air outflow opening |53 is closed. In the opposite position of the valve element |53, controlled by the weight of the elements |60 and |6I, the air inlet I5I is closed and the air outflow |58 is open, allowing the air compressed by the rising water column to flow through the conduit |59 into the air reservoir |02. The conduit |59 may comprise a back pressure valve |64 closing backwards against the water container. The air reservoir is provided with a pressure gauge |65 as well as arconsumption conduit or pipe line |66 comprising a shut-off valve |61. In order to securely avoid ydangerous pressures of the air, the air space in the upper portion ofV the water container may be connected to the atmosphere through a conduit |69 comprising a safe-ty valve (not shown).

In operation, at the beginning of the cycle, the regulator valve |37| and the Water inlet valve |45 are both in the open positions, the discharge valve I I4 is closed, the dischargefvalve |24 is open, the air inlet valve |56 is closed, the air outflow valve |51 is open, and the back pressure Valve |64 is closed. Now, the level of the water supplied through the water inlet |33, Will rise successively, compressing the air tothe normal or maximum pressure of working, the back pressure valve |64 thereby being opened. During this operation also the air receptacle is being filled with air under pressure. When the rising water column arrives at the level of the iioat |26, the discharge opening I2 3 from the float chamber |04 is closed. The normal maximum pressure-of working may be attained when the water outside of the float chamber has attained a certainlevel, for example, the plane of the bottom surface of the iioat chamber. Then, the regulator Valve |3| is shut by the air pressure, and the supply of water is shut off. According to the consumption of air, the air pressure decreases, until the regulator valve |3| is again opened. Now, the water column within the water container rises a further distance until the normal maximum pressure of working is again attained. Thus, the level of the water column rises step by step according to the consumption of the air under pressure.

Finally, the rising water flows into the float chamber |04 over the upper edge or brim of this chamber which is successively filled. The float |08 begins to lift, tensioning the spring ||2, and ultimately lifting the valve rod |01. Now, the air inlet |50 is opened under the action of the valve rod fork |62, and the air outflow opening |58 is closed. Thereby, the air under pressure enclosed in the air space of the container |00, is blown out through the opening |50. The float |6| is a safety means serving to operate the valves |56 and |51 in the event that the float |08 should fail to operate. In the lifting motion of the valve rod |01 the spring- ||3 is tensioned, but the discharge valve I4 does not open until the pressure of the air has been reduced sul'liciently to cause the tens-ion of the spring I3 to balance and overcome the air pressure acting upon the discharge valve H4. rIhus, the discharge valve I4 is opened with a small delay in relation to the lift motion of float |08 and valve rod |01. When the discharge valve |4 is opened, the water inlet |33 is closed by the valve |45. Thus, no water is supplied during the discharge of th-e water container, in spite of the fact that the regulator valve |3| might be open at this time.

The water column in the water container is now sinking, and during this operation fresh air is introduced through the open inlet |50 in dependence on the suction action :caused by the sinking water column, .but the water within the float chamber will not sink at this time. Not until the water outside the iioat chamber has allowed the float 2S to open the valve |24, will the Water of float chamber begin to discharge through the opening |23, and then only at a comparatively low rate. The oat |08 moves downwards and the air inlet |50 is closed. Ultimately the discharge valve |4 is closed and the Water inlet valve |45 is brought to open position, allowing water to be supplied into the water container. Then, the cycle of operation is repeated.

In the embodiment illustrated in Fig. 2, the reference numeral |00 indicates the water container, |0| is the bottom of the same, |02 the air reservoir, |04' the float chamber, |01' the vertical valve rod, |08 the main float, |09 the iioat tube, l the cross pin, I2 the light spring, I3' the heavy spring, ||4 the water discharge valve, |23 a restricted non-controlled discharge opening in the bottom of the float chamber, |30 the water supply conduit, |3| the regulator valve, |40 the air control conduit for said valve, connected from the upper portion of the water container, |45 the water inlet valve operated by a separate iioat and lever mechanism |49', reference numeral |50 indicates the air inlet controlled over a lever mechanism |60' from the vertical rod |01', and reference numeral |58 is the air outow opening which is non-controlled per se but which communicates with the air reservoir |02 over a back pressure valve |64.

The neet chamber 'm4' is securely mounted upon the upper end of a vertical sleeve |15 extending upwards from the bottom |0| of the water receptacle, the restricted opening |23 constituting a connection from the iloat chamberto the interior of said sleeve.|15. The discharge opening is located centrally below said sleeve and is in connection with the interior of said sleeve as well as with the space surrounding said sleeve. The discharge valve H4 has its upper portion located Within said sleeve and is arranged to control not only the discharge from the sleeve |15 but even a discharge openingfrom the space of the water container |00, which discharge opening extends below the lower end of the sleeve |15 and may comprise a number of channels |11. On account of the restricted area of the opening 23 the oat chamber |04 is discharged only when the water container |00 has been substantially discharged. Generally this embodiment operates in the same manner as does the embodiment illustrated in Fig. 1.

Fig. 3 illustrates a water container |00 made as a flushing cistern for urinals. The water container |00 is provided with a cover |03 which is not hermetically sealed to the container. Thus, no air inlet with associate details is necessary,

and of the float mechanism only the following details are used: the iioat chamber |04 which is securely mounted by suitable means (not shown), the guide tube |06, the valve rod |01, the iloat |08, the float tube |09, the cross pin Hi", the light spring ||2, the heavy spring H3, the oat chamber outlet |23, the corresponding control valve |24", and the corresponding float |26. This discharge devices operates in the same manner as has been described in connection with Fig. l.

The water inlet |32 is connected to the upper portion of the cistern and communicates with a tube |33 extending downwards within the cistern. In the upper portion of the cistern there is provided an overflow outlet which communicates through a channel |8| with the space below the discharge valve ||4, thus preventing the cistern from being overlled.

In all embodiments there is used a water discharge device of generally the same type, this device being of a simple design and reliable in operation. When adopted for an hydraulic air compressor, such compressor will deliver an air under pressure which is absolutely clean and odorless, this in contrast to engine compressors in which the air is contaminated by lubricating oil.

Although this invention has been described and illustratedA in relation to specic arrangements, it is to be understood that it is capable of application in other organizations and is, therefore, not to be limited to the particular embodiments disclosed.

What I claim is:

l. A water receptacle, comprising, in combination, a water inlet, a water` discharge opening provided at the bottom of said receptacle, a valve controlling said discharge opening, a oat chamber secured Within said receptacle and having an opening at its upper end, a float vertically guided in said chamber, a vertical rod extending from the interior of said chamber through the bottom of the same downwards to the proximity of said discharge valve, a resilient connection between the lower end of said rod and said discharge valve, a resilient connection between the upper end of said rod and said float, which last-mentioned connection is more elastic than is the re- 7 silientconnectionof j the discharge valve, to allow the discharge valve to open with a delay in rela- 'tion to the lifting movement of the float and discharge means at the float chamber for dischargling said float chamber only when the water receptacle has been. substantially discharged.

2. A water receptacle, comprising, in combination, a Water inlet, a water discharge opening provided at the bottom of said receptacle, a valve controlling,saiddischarge opening, a float chamber Secured within said receptacle and having an opening at its upper end, a float vertically guided in said chamber, a vertical rod extending from the interior of said chamber through the bottom of the same downwards to the proximity of said discharge valve, a resilient connection between the lower end of said rod and said discharge valve, a resilient connection between the upper end of said rod and said float, which last-mentioned connection is more elastic than is the resilient connection of the discharge valve, to allow the discharge valve to open with a delay in relation to the lifting movement of the oat, and a discharge opening at the bottom of `the oat chamber which opening is of such restricted area that. the float chamber is discharged only when the water receptacle has been substantially discharged, to cause the oat to close the discharge A valve only after the water receptacle has been substantially discharged.

3. A water receptacle, comprising, in combination, a water inlet, a Water discharge opening provided at the bottom of said receptacle, a valve controlling said discharge opening, a float chamber secured-within said receptacle and having an opening at its upper end, a float vertically guided in said chamber, a vertical rod extending from the interior of said chamber through the bottom of the same downwards to the proximity of said discharge valve, a resilient connection between the lower end of said rod and said discharge valve, a resilient connection between the upper end of said rod and said oat, which last-mentioned connection is more elastic than is the resilient connection of the discharge valve, to

allow the discharge valveto open witha delay in relation to the lifting movement of the oat, a discharge opening at the bottom of the float chamber, a valve controlling said discharge opening of the float chamber, and an auxiliary float controlling this last-mentioned discharge opening and being provided within the water receptacle, to opensaid Valve when the water in the receptacle has sunk below said auxiliary oat.

4. A water receptacle, comprising, in combination, a water inlet, a water discharge opening provided at the bottom of said receptacle, a-valve controlling said discharge opening, a float chamber secured within said receptacle and being open at its upper end, a rst tube secured in thefbottom of said chamber and extending upwards through said chamber, a float arrangedwithin said chamber and sliding on said tube, a vertical rod extending through said chamber and the bottom thereof to the proximity of said discharge valve, aspring connectionbetween thelower end of said rod and said discharge valve, a second tube secured on Vthe upper side of the float and extending upwards, Vtwo diametrically opposed slots in said second tube which slots extend from the lower portion of said second tube and to a point nearfthe upper end of said second tube, a cross pinsecured in said rod and projecting through saidfslots, anda-helicalsprng arranged between said cross pin and the upper side of said float, which spring is weaker than is the resilient connection vof the discharge valve, to, allow the discharge valve to open with a delay in relation to the lifting'movement of the float.

5. Water receptacle discharge control and air compressing apparatus, comprising, in combination, a water receptacle, a hermetic closure for said receptacle, a water supply conduit, a valve controlling said water supply, a water discharge opening provided at the bottom of said receptacle, a valve controllingsaid discharge opening, a float chamber secured within said receptacle and being open at its upper end, a float vertically guided in said chamber, a vertical rod extending through said chamber andN its bottom to apoint4 near said discharge valve, a first resilient connection between the lower end of said rod and said discharge valve, a second resilient connection between the upper end of said rod and said float, this last-mentioned resilient connection being more elastic than is the resilient connection of the discharge valve, to allow the discharge valve to open with a delay in relation to the lifting movement of the oat, discharge means at the bottom of the float chamber, to discharge said chamber only after the water receptacle is substantially discharged and, thus, to cause the float to close the discharge valve of the water receptacle only after the water Vreceptacle has been substantially discharged, an air inlet opening provided in the upper portion of the water receptacle, a valve controlling this air inlet, and a conduit connected to said upper portion of the receptacle, to constitute a consumption conduit for air under pressure, compressed by the rising water column within the receptacle.

6. Apparatus according toclaim 5, and comprising, in combination, means for an automatic operation of said Water supply valve in dependence on the air pressure in the'upper portion of the water receptacle, to open this valve at an air pressure below the normal pressure of working and to close this valve at the normal pressure of working, the water level in the receptacle thus rising step by step according yto the consumption of air under pressure.

7. Apparatus according to claim 5, and also comprising, in combination, a spring normally holding said water supply valve in open position, an airtight chamber connected with .the upper portion of the water receptacle, a'movable wall lelement in said air tight chamber, connected with said water supply valve to close the same when the air pressure within said airtight chamber attains a higher value.

8. Apparatus according to claim 5, and also comprising, in combination, a shut-01T valve in said water supply conduit, which valve is normally in open position, and means operating in dependence on the water level in the water receptacle to cause said shut-oir valve to cut off the water'supply when the receptacle is substantially lled.

9. Apparatus according to claim 5, and also comprising, in combination, means operating said air inlet valve Ain dependence on the water level insaid float chamber, to open said air inlet valve when the float chamber is substantially filled, whereby any air under high pressure is blown out before the delayed discharge of the receptacle and fresh air is supplied when the water level sinks.

10. Apparatus according to claim 5, and also comprising, in combination, means under control by said float and connected with said air inlet valve to open said air inlet valve when the float chamber is substantially filled, whereby any air under pressure is blown out before the delayed discharge of the receptacle and fresh air is supplied when the water level sinks.

l1. Apparatus according to claim 5, and also comprising, in combination, an air reservoir, a conduit supplying air from the upper portion of the water receptacle into said air reservoir, and a back pressure valve in said conduit.

12. Apparatus according to claim 5, and also comprising, in combination, an air reservoir, a conduit supplying air from the upper portion of the water receptacle into said reservoir, a supply valve in said supply conduit, and means operating said supply valve in dependence on the water level in said oat chamber to close said valve when the water receptacle is substantially lled with water. f

13. Apparatus according to claim 5, and also comprising, in combination, an air reservoir, a conduit supplying air from the upper portion of the water receptacle into said reservoir, a valve controlling the ow of air in said air supply conduit, an air consumption conduit connected to said air reservoir, and a shut-off valve in said consumption conduit.

14. A water receptacle, comprising, in combination, a water inlet, a vertical sleeve extending upwards from the bottom of said receptacle, a discharge opening located concentrically below said sleeve and in connection with the interior of said sleeve as well as with the space surrounding said sleeve, a valve controlling said discharge l0 opening, a float chamber secured on the upper terminal of said sleeve within said receptacle and open at its upper end surface, a float vertically guided in said chamber, a vertical rod extending from the interior of said chamber through said sleeve to a point near said discharge valve, a first resilient connection between the lower end of said rod and' said discharge valve, a second resilient connection between the upper end of said rod and said float, which second resilient connection is more elastic than is the first resilient connection, to allow the discharge valve to open with a delay in relation to the lift movement of the float, and a discharge opening in the bottom of the float chamber which opening is of a restricted area such as to cause the oat chamber to be discharged only When-the water receptacle has been substantially discharged, and thus to cause the iioat to close the discharge valve only when the water receptacle has been substantially discharged.

EDVIN SJBERG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,077,832 Gebert Apr. 20, 1937 FOREIGN PATENTS Number Country Date 523,281 France Aug. 16, 1921 

